[PATCH 0/2] proc: use subset option to hide some top-level procfs entries

From: Alexey Gladkov
Date: Thu Jun 04 2020 - 16:04:37 EST


Greetings!

Preface
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This patch set can be applied over:

git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace.git d35bec8a5788

Overview
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Directories and files can be created and deleted by dynamically loaded modules.
Not all of these files are virtualized and safe inside the container.

However, subset=pid is not enough because many containers wants to have
/proc/meminfo, /proc/cpuinfo, etc. We need a way to limit the visibility of
files per procfs mountpoint.

Introduced changes
------------------
Allow to specify the names of files and directories in the subset= parameter and
thereby make a whitelist of top-level permitted names.


Alexey Gladkov (2):
proc: use subset option to hide some top-level procfs entries
docs: proc: update documentation about subset= parameter

Documentation/filesystems/proc.rst | 6 +++
fs/proc/base.c | 15 +++++-
fs/proc/generic.c | 75 +++++++++++++++++++++------
fs/proc/inode.c | 18 ++++---
fs/proc/internal.h | 12 +++++
fs/proc/root.c | 81 ++++++++++++++++++++++++------
include/linux/proc_fs.h | 11 ++--
7 files changed, 175 insertions(+), 43 deletions(-)

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2.25.4